The start of each cycle of a pump, which supplies a pressurized ink stream through a nozzle for application to a recording surface on a rotary drum, is synchronized with each revolution of the drum. If more than one cycle of the pump occurs during each revolution of the drum, the number of the cycles...http://www.google.de/patents/US4146901?utm_source=gb-gplus-sharePatent US4146901 - Apparatus for recording information on a recording surface
